Makes send_file work again by deferring to Rack::Sendfile.

  * Add the Rack::Sendfile middleware
  * Make the header to use configurable via config.action_dispatch.x_sendfile_header (default to "X-Sendfile"). 
  * Add Railties tests to confirm that these work
  * Remove the :stream, :buffer_size, and :x_senfile default options to send_file
  * Change the log subscriber to always say "Sent file"
  * Add deprecation warnings for options that are now no-ops

Note that servers can configure this by setting X-Sendfile-Type. Hosting companies and those creating packages of servers specially designed for Rails applications are encouraged to specify this header so that this can work transparently.

3 files changed, 22 insertions, 47 deletions

diff --git a/actionpack/lib/action_controller/metal/streaming.rb b/actionpack/lib/action_controller/metal/streaming.rb
index 0d6fdafe0a..753af3dc58 100644
--- a/actionpack/lib/action_controller/metal/streaming.rb
+++ b/actionpack/lib/action_controller/metal/streaming.rb
@@ -9,18 +9,13 @@ module ActionController #:nodoc:
     DEFAULT_SEND_FILE_OPTIONS = {
       :type         => 'application/octet-stream'.freeze,
       :disposition  => 'attachment'.freeze,
-      :stream       => true,
-      :buffer_size  => 4096,
-      :x_sendfile   => false
     }.freeze
 
-    X_SENDFILE_HEADER = 'X-Sendfile'.freeze
-
     protected
-      # Sends the file, by default streaming it 4096 bytes at a time. This way the
-      # whole file doesn't need to be read into memory at once. This makes it
-      # feasible to send even large files. You can optionally turn off streaming
-      # and send the whole file at once.
+      # Sends the file. This uses a server-appropriate method (such as X-Sendfile)
+      # via the Rack::Sendfile middleware. The header to use is set via
+      # config.action_dispatch.x_sendfile_header, and defaults to "X-Sendfile".
+      # Your server can also configure this for you by setting the X-Sendfile-Type header.
       #
       # Be careful to sanitize the path parameter if it is coming from a web
       # page. <tt>send_file(params[:path])</tt> allows a malicious user to
@@ -31,24 +26,12 @@ module ActionController #:nodoc:
       #   Defaults to <tt>File.basename(path)</tt>.
       # * <tt>:type</tt> - specifies an HTTP content type. Defaults to 'application/octet-stream'. You can specify
       #   either a string or a symbol for a registered type register with <tt>Mime::Type.register</tt>, for example :json
-      # * <tt>:length</tt> - used to manually override the length (in bytes) of the content that
-      #   is going to be sent to the client. Defaults to <tt>File.size(path)</tt>.
       # * <tt>:disposition</tt> - specifies whether the file will be shown inline or downloaded.
       #   Valid values are 'inline' and 'attachment' (default).
-      # * <tt>:stream</tt> - whether to send the file to the user agent as it is read (+true+)
-      #   or to read the entire file before sending (+false+). Defaults to +true+.
-      # * <tt>:buffer_size</tt> - specifies size (in bytes) of the buffer used to stream the file.
-      #   Defaults to 4096.
       # * <tt>:status</tt> - specifies the status code to send with the response. Defaults to '200 OK'.
       # * <tt>:url_based_filename</tt> - set to +true+ if you want the browser guess the filename from
       #   the URL, which is necessary for i18n filenames on certain browsers
       #   (setting <tt>:filename</tt> overrides this option).
-      # * <tt>:x_sendfile</tt> - uses X-Sendfile to send the file when set to +true+. This is currently
-      #   only available with Lighttpd/Apache2 and specific modules installed and activated. Since this
-      #   uses the web server to send the file, this may lower memory consumption on your server and
-      #   it will not block your application for further requests.
-      #   See http://blog.lighttpd.net/articles/2006/07/02/x-sendfile and
-      #   http://tn123.ath.cx/mod_xsendfile/ for details. Defaults to +false+.
       #
       # The default Content-Type and Content-Disposition headers are
       # set to download arbitrary binary files in as many browsers as
@@ -79,23 +62,18 @@ module ActionController #:nodoc:
       # http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9
       # for the Cache-Control header spec.
       def send_file(path, options = {}) #:doc:
-        # self.response_body = File.open(path)
-
         raise MissingFile, "Cannot read file #{path}" unless File.file?(path) and File.readable?(path)
 
-        options[:length]   ||= File.size(path)
         options[:filename] ||= File.basename(path) unless options[:url_based_filename]
         send_file_headers! options
 
-        @performed_render = false
-
         if options[:x_sendfile]
-          head options[:status], X_SENDFILE_HEADER => path
-        else
-          self.status = options[:status] || 200
-          self.content_type = options[:content_type] if options.key?(:content_type)
-          self.response_body = File.open(path, "rb")
+          ActiveSupport::Deprecation.warn(":x_sendfile is no longer needed in send_file", caller)
         end
+
+        self.status = options[:status] || 200
+        self.content_type = options[:content_type] if options.key?(:content_type)
+        self.response_body = File.open(path, "rb")
       end
 
       # Sends the given binary data to the browser. This method is similar to
@@ -130,32 +108,35 @@ module ActionController #:nodoc:
       # data to the browser, then use <tt>render :text => proc { ... }</tt>
       # instead. See ActionController::Base#render for more information.
       def send_data(data, options = {}) #:doc:
-        send_file_headers! options.merge(:length => data.bytesize)
+        send_file_headers! options.dup
         render options.slice(:status, :content_type).merge(:text => data)
       end
 
     private
       def send_file_headers!(options)
         options.update(DEFAULT_SEND_FILE_OPTIONS.merge(options))
-        [:length, :type, :disposition].each do |arg|
+        [:type, :disposition].each do |arg|
           raise ArgumentError, ":#{arg} option required" if options[arg].nil?
         end
 
-        disposition = options[:disposition].dup || 'attachment'
+        if options.key?(:length)
+          ActiveSupport::Deprecation.warn("You do not need to provide the file's length", caller)
+        end
 
-        disposition <<= %(; filename="#{options[:filename]}") if options[:filename]
+        disposition = options[:disposition]
+        disposition += %(; filename="#{options[:filename]}") if options[:filename]
 
         content_type = options[:type]
 
         if content_type.is_a?(Symbol)
-          raise ArgumentError, "Unknown MIME type #{options[:type]}" unless Mime::EXTENSION_LOOKUP.key?(content_type.to_s)
-          self.content_type = Mime::Type.lookup_by_extension(content_type.to_s)
+          extension = Mime[content_type]
+          raise ArgumentError, "Unknown MIME type #{options[:type]}" unless extension
+          self.content_type = extension
         else
           self.content_type = content_type
         end
 
         headers.merge!(
-          'Content-Length'            => options[:length].to_s,
           'Content-Disposition'       => disposition,
           'Content-Transfer-Encoding' => 'binary'
         )
diff --git a/actionpack/lib/action_controller/railties/log_subscriber.rb b/actionpack/lib/action_controller/railties/log_subscriber.rb
index df9ffa1717..c2299d0b05 100644
--- a/actionpack/lib/action_controller/railties/log_subscriber.rb
+++ b/actionpack/lib/action_controller/railties/log_subscriber.rb
@@ -22,15 +22,7 @@ module ActionController
       end
 
       def send_file(event)
-        message = if event.payload[:x_sendfile]
-          header = ActionController::Streaming::X_SENDFILE_HEADER
-          "Sent #{header} header %s"
-        elsif event.payload[:stream]
-          "Streamed file %s"
-        else
-          "Sent file %s"
-        end
-
+        message = "Sent file %s"
         message << " (%.1fms)"
         info(message % [event.payload[:path], event.duration])
       end
diff --git a/actionpack/lib/action_dispatch/railtie.rb b/actionpack/lib/action_dispatch/railtie.rb
index 335daafc01..79e9464337 100644
--- a/actionpack/lib/action_dispatch/railtie.rb
+++ b/actionpack/lib/action_dispatch/railtie.rb
@@ -5,6 +5,8 @@ module ActionDispatch
   class Railtie < Rails::Railtie
     railtie_name :action_dispatch
 
+    config.action_dispatch.x_sendfile_header = "X-Sendfile"
+
     # Prepare dispatcher callbacks and run 'prepare' callbacks
     initializer "action_dispatch.prepare_dispatcher" do |app|
       # TODO: This used to say unless defined?(Dispatcher). Find out why and fix.